474 lines
17 KiB
Plaintext
474 lines
17 KiB
Plaintext
# mmap(2) blacklisting. Some platforms provide the mmap library routine
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# but don't support all of the features we need from it.
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AC_DEFUN([AC_FUNC_MMAP_BLACKLIST],
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[
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AC_CHECK_HEADER([sys/mman.h],
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[libffi_header_sys_mman_h=yes], [libffi_header_sys_mman_h=no])
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AC_CHECK_FUNC([mmap], [libffi_func_mmap=yes], [libffi_func_mmap=no])
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if test "$libffi_header_sys_mman_h" != yes \
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|| test "$libffi_func_mmap" != yes; then
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ac_cv_func_mmap_file=no
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ac_cv_func_mmap_dev_zero=no
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ac_cv_func_mmap_anon=no
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else
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AC_CACHE_CHECK([whether read-only mmap of a plain file works],
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ac_cv_func_mmap_file,
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[# Add a system to this blacklist if
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# mmap(0, stat_size, PROT_READ, MAP_PRIVATE, fd, 0) doesn't return a
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# memory area containing the same data that you'd get if you applied
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# read() to the same fd. The only system known to have a problem here
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# is VMS, where text files have record structure.
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case "$host_os" in
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vms* | ultrix*)
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ac_cv_func_mmap_file=no ;;
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*)
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ac_cv_func_mmap_file=yes;;
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esac])
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AC_CACHE_CHECK([whether mmap from /dev/zero works],
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ac_cv_func_mmap_dev_zero,
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[# Add a system to this blacklist if it has mmap() but /dev/zero
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# does not exist, or if mmapping /dev/zero does not give anonymous
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# zeroed pages with both the following properties:
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# 1. If you map N consecutive pages in with one call, and then
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# unmap any subset of those pages, the pages that were not
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# explicitly unmapped remain accessible.
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# 2. If you map two adjacent blocks of memory and then unmap them
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# both at once, they must both go away.
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# Systems known to be in this category are Windows (all variants),
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# VMS, and Darwin.
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case "$host_os" in
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vms* | cygwin* | pe | mingw* | darwin* | ultrix* | hpux10* | hpux11.00)
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ac_cv_func_mmap_dev_zero=no ;;
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*)
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ac_cv_func_mmap_dev_zero=yes;;
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esac])
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# Unlike /dev/zero, the MAP_ANON(YMOUS) defines can be probed for.
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AC_CACHE_CHECK([for MAP_ANON(YMOUS)], ac_cv_decl_map_anon,
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[AC_TRY_COMPILE(
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[#include <sys/types.h>
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#include <sys/mman.h>
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#include <unistd.h>
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#ifndef MAP_ANONYMOUS
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#define MAP_ANONYMOUS MAP_ANON
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#endif
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],
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[int n = MAP_ANONYMOUS;],
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ac_cv_decl_map_anon=yes,
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ac_cv_decl_map_anon=no)])
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if test $ac_cv_decl_map_anon = no; then
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ac_cv_func_mmap_anon=no
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else
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AC_CACHE_CHECK([whether mmap with MAP_ANON(YMOUS) works],
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ac_cv_func_mmap_anon,
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[# Add a system to this blacklist if it has mmap() and MAP_ANON or
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# MAP_ANONYMOUS, but using mmap(..., MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
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# doesn't give anonymous zeroed pages with the same properties listed
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# above for use of /dev/zero.
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# Systems known to be in this category are Windows, VMS, and SCO Unix.
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case "$host_os" in
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vms* | cygwin* | pe | mingw* | sco* | udk* )
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ac_cv_func_mmap_anon=no ;;
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*)
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ac_cv_func_mmap_anon=yes;;
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esac])
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fi
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fi
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if test $ac_cv_func_mmap_file = yes; then
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AC_DEFINE(HAVE_MMAP_FILE, 1,
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[Define if read-only mmap of a plain file works.])
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fi
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if test $ac_cv_func_mmap_dev_zero = yes; then
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AC_DEFINE(HAVE_MMAP_DEV_ZERO, 1,
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[Define if mmap of /dev/zero works.])
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fi
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if test $ac_cv_func_mmap_anon = yes; then
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AC_DEFINE(HAVE_MMAP_ANON, 1,
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[Define if mmap with MAP_ANON(YMOUS) works.])
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fi
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])
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dnl ----------------------------------------------------------------------
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dnl This whole bit snagged from libstdc++-v3, via libatomic.
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dnl
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dnl LIBAT_ENABLE
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dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
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dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
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dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
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dnl
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dnl See docs/html/17_intro/configury.html#enable for documentation.
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dnl
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m4_define([LIBAT_ENABLE],[dnl
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m4_define([_g_switch],[--enable-$1])dnl
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m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
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AC_ARG_ENABLE($1,_g_help,
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m4_bmatch([$5],
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[^permit ],
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[[
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case "$enableval" in
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m4_bpatsubst([$5],[permit ])) ;;
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*) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
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dnl Idea for future: generate a URL pointing to
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dnl "onlinedocs/configopts.html#whatever"
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esac
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]],
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[^$],
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[[
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case "$enableval" in
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yes|no) ;;
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*) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
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esac
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]],
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[[$5]]),
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[enable_]m4_bpatsubst([$1],-,_)[=][$2])
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m4_undefine([_g_switch])dnl
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m4_undefine([_g_help])dnl
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])
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dnl
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dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
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dnl the native linker is in use, all variables will be defined to something
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dnl safe (like an empty string).
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dnl
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dnl Defines:
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dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
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dnl OPT_LDFLAGS='-Wl,-O1' if possible
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dnl LD (as a side effect of testing)
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dnl Sets:
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dnl with_gnu_ld
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dnl libat_ld_is_gold (possibly)
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dnl libat_gnu_ld_version (possibly)
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dnl
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dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
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dnl set libat_gnu_ld_version to 12345. Zeros cause problems.
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dnl
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AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [
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# If we're not using GNU ld, then there's no point in even trying these
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# tests. Check for that first. We should have already tested for gld
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# by now (in libtool), but require it now just to be safe...
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test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
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test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
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AC_REQUIRE([AC_PROG_LD])
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AC_REQUIRE([AC_PROG_AWK])
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# The name set by libtool depends on the version of libtool. Shame on us
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# for depending on an impl detail, but c'est la vie. Older versions used
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# ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
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# top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
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# makes sense). We'll test with_gnu_ld everywhere else, so if that isn't
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# set (hence we're using an older libtool), then set it.
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if test x${with_gnu_ld+set} != xset; then
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if test x${ac_cv_prog_gnu_ld+set} != xset; then
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# We got through "ac_require(ac_prog_ld)" and still not set? Huh?
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with_gnu_ld=no
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else
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with_gnu_ld=$ac_cv_prog_gnu_ld
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fi
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fi
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# Start by getting the version number. I think the libtool test already
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# does some of this, but throws away the result.
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libat_ld_is_gold=no
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if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
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libat_ld_is_gold=yes
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fi
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changequote(,)
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ldver=`$LD --version 2>/dev/null |
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sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
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changequote([,])
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libat_gnu_ld_version=`echo $ldver | \
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$AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
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# Set --gc-sections.
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if test "$with_gnu_ld" = "notbroken"; then
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# GNU ld it is! Joy and bunny rabbits!
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# All these tests are for C++; save the language and the compiler flags.
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# Need to do this so that g++ won't try to link in libstdc++
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ac_test_CFLAGS="${CFLAGS+set}"
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ac_save_CFLAGS="$CFLAGS"
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CFLAGS='-x c++ -Wl,--gc-sections'
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# Check for -Wl,--gc-sections
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# XXX This test is broken at the moment, as symbols required for linking
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# are now in libsupc++ (not built yet). In addition, this test has
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# cored on solaris in the past. In addition, --gc-sections doesn't
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# really work at the moment (keeps on discarding used sections, first
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# .eh_frame and now some of the glibc sections for iconv).
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# Bzzzzt. Thanks for playing, maybe next time.
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AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
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AC_TRY_RUN([
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int main(void)
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{
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try { throw 1; }
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catch (...) { };
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return 0;
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}
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], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
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if test "$ac_test_CFLAGS" = set; then
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CFLAGS="$ac_save_CFLAGS"
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else
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# this is the suspicious part
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CFLAGS=''
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fi
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if test "$ac_sectionLDflags" = "yes"; then
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SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
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fi
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AC_MSG_RESULT($ac_sectionLDflags)
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fi
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# Set linker optimization flags.
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if test x"$with_gnu_ld" = x"yes"; then
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OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
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fi
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AC_SUBST(SECTION_LDFLAGS)
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AC_SUBST(OPT_LDFLAGS)
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])
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dnl
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dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
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dnl the native linker is in use, all variables will be defined to something
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dnl safe (like an empty string).
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dnl
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dnl Defines:
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dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
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dnl OPT_LDFLAGS='-Wl,-O1' if possible
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dnl LD (as a side effect of testing)
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dnl Sets:
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dnl with_gnu_ld
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dnl libat_ld_is_gold (possibly)
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dnl libat_gnu_ld_version (possibly)
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dnl
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dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
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dnl set libat_gnu_ld_version to 12345. Zeros cause problems.
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dnl
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AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [
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# If we're not using GNU ld, then there's no point in even trying these
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# tests. Check for that first. We should have already tested for gld
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# by now (in libtool), but require it now just to be safe...
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test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
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test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
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AC_REQUIRE([AC_PROG_LD])
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AC_REQUIRE([AC_PROG_AWK])
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# The name set by libtool depends on the version of libtool. Shame on us
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# for depending on an impl detail, but c'est la vie. Older versions used
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# ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
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# top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
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# makes sense). We'll test with_gnu_ld everywhere else, so if that isn't
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# set (hence we're using an older libtool), then set it.
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if test x${with_gnu_ld+set} != xset; then
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if test x${ac_cv_prog_gnu_ld+set} != xset; then
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# We got through "ac_require(ac_prog_ld)" and still not set? Huh?
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with_gnu_ld=no
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else
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with_gnu_ld=$ac_cv_prog_gnu_ld
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fi
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fi
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# Start by getting the version number. I think the libtool test already
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# does some of this, but throws away the result.
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libat_ld_is_gold=no
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if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
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libat_ld_is_gold=yes
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fi
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changequote(,)
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ldver=`$LD --version 2>/dev/null |
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sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
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changequote([,])
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libat_gnu_ld_version=`echo $ldver | \
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$AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
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# Set --gc-sections.
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if test "$with_gnu_ld" = "notbroken"; then
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# GNU ld it is! Joy and bunny rabbits!
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# All these tests are for C++; save the language and the compiler flags.
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# Need to do this so that g++ won't try to link in libstdc++
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ac_test_CFLAGS="${CFLAGS+set}"
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ac_save_CFLAGS="$CFLAGS"
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CFLAGS='-x c++ -Wl,--gc-sections'
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# Check for -Wl,--gc-sections
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# XXX This test is broken at the moment, as symbols required for linking
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# are now in libsupc++ (not built yet). In addition, this test has
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# cored on solaris in the past. In addition, --gc-sections doesn't
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# really work at the moment (keeps on discarding used sections, first
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# .eh_frame and now some of the glibc sections for iconv).
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# Bzzzzt. Thanks for playing, maybe next time.
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AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
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AC_TRY_RUN([
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int main(void)
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{
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try { throw 1; }
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catch (...) { };
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return 0;
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}
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], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
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if test "$ac_test_CFLAGS" = set; then
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CFLAGS="$ac_save_CFLAGS"
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else
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# this is the suspicious part
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CFLAGS=''
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fi
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if test "$ac_sectionLDflags" = "yes"; then
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SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
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fi
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AC_MSG_RESULT($ac_sectionLDflags)
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fi
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# Set linker optimization flags.
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if test x"$with_gnu_ld" = x"yes"; then
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OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
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fi
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AC_SUBST(SECTION_LDFLAGS)
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AC_SUBST(OPT_LDFLAGS)
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])
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dnl
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dnl Add version tags to symbols in shared library (or not), additionally
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dnl marking other symbols as private/local (or not).
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dnl
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dnl --enable-symvers=style adds a version script to the linker call when
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dnl creating the shared library. The choice of version script is
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dnl controlled by 'style'.
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dnl --disable-symvers does not.
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dnl + Usage: LIBAT_ENABLE_SYMVERS[(DEFAULT)]
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dnl Where DEFAULT is either 'yes' or 'no'. Passing `yes' tries to
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dnl choose a default style based on linker characteristics. Passing
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dnl 'no' disables versioning.
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dnl
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AC_DEFUN([LIBAT_ENABLE_SYMVERS], [
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LIBAT_ENABLE(symvers,yes,[=STYLE],
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[enables symbol versioning of the shared library],
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[permit yes|no|gnu*|sun])
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# If we never went through the LIBAT_CHECK_LINKER_FEATURES macro, then we
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# don't know enough about $LD to do tricks...
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AC_REQUIRE([LIBAT_CHECK_LINKER_FEATURES])
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# Turn a 'yes' into a suitable default.
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|
if test x$enable_symvers = xyes ; then
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# FIXME The following test is too strict, in theory.
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if test $enable_shared = no || test "x$LD" = x; then
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enable_symvers=no
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else
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if test $with_gnu_ld = yes ; then
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enable_symvers=gnu
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else
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case ${target_os} in
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# Sun symbol versioning exists since Solaris 2.5.
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solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
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enable_symvers=sun ;;
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*)
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enable_symvers=no ;;
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esac
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fi
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fi
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fi
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# Check if 'sun' was requested on non-Solaris 2 platforms.
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if test x$enable_symvers = xsun ; then
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case ${target_os} in
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solaris2*)
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# All fine.
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;;
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*)
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# Unlikely to work.
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AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
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AC_MSG_WARN([=== you are not targetting Solaris 2.])
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AC_MSG_WARN([=== Symbol versioning will be disabled.])
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enable_symvers=no
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;;
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esac
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fi
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# Check to see if libgcc_s exists, indicating that shared libgcc is possible.
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if test $enable_symvers != no; then
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AC_MSG_CHECKING([for shared libgcc])
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ac_save_CFLAGS="$CFLAGS"
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CFLAGS=' -lgcc_s'
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AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes, libat_shared_libgcc=no)
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CFLAGS="$ac_save_CFLAGS"
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if test $libat_shared_libgcc = no; then
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cat > conftest.c <<EOF
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int main (void) { return 0; }
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EOF
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changequote(,)dnl
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libat_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
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-shared -shared-libgcc -o conftest.so \
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conftest.c -v 2>&1 >/dev/null \
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| sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
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changequote([,])dnl
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rm -f conftest.c conftest.so
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if test x${libat_libgcc_s_suffix+set} = xset; then
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CFLAGS=" -lgcc_s$libat_libgcc_s_suffix"
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AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes)
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CFLAGS="$ac_save_CFLAGS"
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fi
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fi
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AC_MSG_RESULT($libat_shared_libgcc)
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fi
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# For GNU ld, we need at least this version. The format is described in
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# LIBAT_CHECK_LINKER_FEATURES above.
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libat_min_gnu_ld_version=21400
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# XXXXXXXXXXX libat_gnu_ld_version=21390
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# Check to see if unspecified "yes" value can win, given results above.
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# Change "yes" into either "no" or a style name.
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|
if test $enable_symvers != no && test $libat_shared_libgcc = yes; then
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|
if test $with_gnu_ld = yes; then
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|
if test $libat_gnu_ld_version -ge $libat_min_gnu_ld_version ; then
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enable_symvers=gnu
|
|
elif test $libat_ld_is_gold = yes ; then
|
|
enable_symvers=gnu
|
|
else
|
|
# The right tools, the right setup, but too old. Fallbacks?
|
|
AC_MSG_WARN(=== Linker version $libat_gnu_ld_version is too old for)
|
|
AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
|
|
AC_MSG_WARN(=== You would need to upgrade your binutils to version)
|
|
AC_MSG_WARN(=== $libat_min_gnu_ld_version or later and rebuild GCC.)
|
|
if test $libat_gnu_ld_version -ge 21200 ; then
|
|
# Globbing fix is present, proper block support is not.
|
|
dnl AC_MSG_WARN([=== Dude, you are soooo close. Maybe we can fake it.])
|
|
dnl enable_symvers=???
|
|
AC_MSG_WARN([=== Symbol versioning will be disabled.])
|
|
enable_symvers=no
|
|
else
|
|
# 2.11 or older.
|
|
AC_MSG_WARN([=== Symbol versioning will be disabled.])
|
|
enable_symvers=no
|
|
fi
|
|
fi
|
|
elif test $enable_symvers = sun; then
|
|
: All interesting versions of Sun ld support sun style symbol versioning.
|
|
else
|
|
# just fail for now
|
|
AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
|
|
AC_MSG_WARN([=== either you are not using a supported linker, or you are])
|
|
AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
|
|
AC_MSG_WARN([=== Symbol versioning will be disabled.])
|
|
enable_symvers=no
|
|
fi
|
|
fi
|
|
if test $enable_symvers = gnu; then
|
|
AC_DEFINE(LIBAT_GNU_SYMBOL_VERSIONING, 1,
|
|
[Define to 1 if GNU symbol versioning is used for libatomic.])
|
|
fi
|
|
|
|
AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
|
|
AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
|
|
AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
|
|
AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
|
|
])
|